• Plant Resources
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• v.3 no.3
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• pp.219-222
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• 2000

For the purpose of establishing an efficient propagation through airlift bioreactor system of Zingiber of officinale Rosc. Korean native Seosanjong, the effect of different factors and bioreactor on cultured plantlets were investigated. The highest number of plantlets, fresh weight per plant was obtained from explants when cultured in MS liquid medium including 0.3 mg/L NAA and 2.0 mg/L kinetin for 40 days. A 10 L bottle type bubble bioreactor, compared with 250 mL Erlenmeyer flask, was more efficient, producing 4.7 plantlets or from 1.5 to 1.6 times more than did the Erlenmeyer flask. The results demonstrate the rapid mass propagation of airlift bioreactor to produce normal ginger.

• Journal of Environmental Health Sciences
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• v.30 no.1
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• pp.7-14
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• 2004

The change in filamentous bacteria appearance was observed by adjusting factors such as organic and nurient concentration of feed wastewater and the aeration rate in the reactor. In case that COD:N:P and DO were 100:10:1 and 6.1 m1/1 respectively, the mean SVI was 122 ml/g and the filaments were developed normally in flocs. For the low DO con- dition, however, the SVI averaged 186 ml/g and the appearance of outgrowing filaments were more frequent. When the high organic was supplied into the reactor, the average SVI was 274 ml/g and the distinct filamentous bulking was observed. Meanwhile when COD:N:P was maintained at 100: 1 :0.5, the SVI was as low as 87 ml/g and the appearance of filaments were minimal and the size of flocs was small comparing other experimental conditions. For normal, low aeration and high organic concentration, predominant filaments in the early stage of experiments were commonly Type 021N,S. natans which were usually found in low DO condition. However, Type 041, Type 1851, Type 0961 became predominant as experiments extended. Meanwhile, in low nutrient condition, Type 0675, Type 1851, and Type 0961 were observed. The filamentous bacteria appearance for SVI< 150(ml/g), Type 0041, Type 0961 (usually low organic in feed wastewater) were predominantly observed and SVI > 150(ml/g), S. natans and Type 021N(usually low DO in aeration basin) was predominant.

• Journal of Korean Society on Water Environment
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• v.24 no.3
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• pp.328-332
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• 2008

This research was about T-N removal efficiency of oxic reactor in which fixed media submerged from Membrane BNR(An+Ax+Ox) process. This experiment was implemented by using fixed media and changing DO concentration in the oxic reactor. Nitrification efficiencies of all modes were more than 98%. When no media was in the oxic reactor, T-N removal efficiency was only 47.4%, while it were shown from 60.3% to 67.4% with packed media, which indicated improved efficiency of 27~42%. The removal efficiencies of TCOD and BOD were more than 89%, 98% respectively, which could satisfy the guideline of advanced sewage reclamation by Department of Environment. When DO concentration in the packed oxic-media tank was 0.5~1.0 mg/L, T-N removal efficiency was low, which resulted from insufficient nitrification in the oxic reactor. Therefore, DO concentration of bulk solution needs to be kept more than 1.0 mg/L to induce higher nitrification efficiency in the reactor in which media was submerged. Also, the selection of DO concentration is important to prevent media from being clogged.

• Korean Journal of Veterinary Research
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• v.9 no.2
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• pp.7-18
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• 1969

Researches to determine the infectious status on the pancreatic fluke, Eurytrema pancreaticum(Janson 1889) Looss, 1907, were made into several slaughter hauses at four different districts through seven years from 1963 to 1969. The infection rate showed 2962 positive of 5974 heads (49.6%) of cattle at the Seoul first slaughter hause in Seoul, 881 positive of 1021 heads (86.3%) in Cheju, and six(6) positive of 56 heads (11.1%) at Suwon, 58 positive of 306 heads(19.0%)at Joenju. The infection rate 53.1%, (2907 positive heads of total 7357 heads exammed) is the representative infection rate at the cattle eurytremiasis in Korea. It showed little variation through a year and was increased as compared with those of the past period, from 1915 to 1945. Fecal examinations in order to find out the local distribution of the pancreatic fluke were conducted on cattle, sheep, and goats raised in four districts, showing two(2) of 269 heads (0.7%) in Kyonggi-do, 41 of 212 heads (19.3%) in Cheju-do, and negative in both Chungnam-do and Joenbuk-do. When an artificial infection wss performed on rabbits and goats with metacercaria of the pancreatic fluke, Parenchyma of their pancreas were degenerated and the ducts were dilated. When cattle and sheep were infected naturally, the pancreatic ducts were also dilated, the wall was thickened, and adenomatous and epithelial hyperplasia was appeared. The conclusion, putting the foregoing pathological changes, has been arrived at chronic hyperplastic pancreatitis in the eurytremiasis of cattle, sheep, goats and rabbits.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.527-530
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• 2006

Because price of fossil fuel rises, necessity about alternative energy was risen. Studied co-combustion of RPF to coal fluid bed boiler by necessity of these althernative energy. Purpose of this study to coal fluid bed bioler RPF when did co-combustion, change operating condition and characteristic of air pollutant examine according to change of fuel characteristic, operating condition examined about combustion chamber temperature, oxygen content etc. and air pollutant examined about material that is included to allowable exhaust standard and dioxin. Co-combustion condition was 5%. It was no peculiar under test result operating condition. Concentration of Co and HCl rose according as do RPF co-combustion and the other pollutants had hardly changed. Dioxin is low concentration level more than $0.1ng-TEQ/Sm^3$. There was no pollutant that exceed akllowable exhaust standard for boiler but $SO_x,\;NO_x$ were exceeded about allowable exhaust standard for incinerating facility.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.177-179
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• 2002

The process for the production of mannitol with fructose (5% to 25%) using Leuconostoc mesenteroides NRRL B-1149 was investigated. Optimization study for mannitol production was carried out in 8 liter batch or fed-batch cultures at $28^{\circ}C$, pH 5.0, without aeration. When 5% fructose was used in a batch culture fermentation, the yield of mannitol was 78% of theoretical. As the concentration of fructose was increased to 10% in a batch culture, the yield was reduced to 59.6% of theoretical. Using a fed-batch fermentation with 10% fructose, the yield was increased to 81.9%. When 15% fructose was used for a fed batch fermentation 5% fructose was initially added and the last 10% fructose was supplied continuously. The final yield of mannitol was 83.71% of theoretical. When 20% fructose was used, the yield was more higher, 89.48%.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2001.11a
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• pp.77-82
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• 2001

This paper is contents that measure the ventilation rates and temperature by driving condition of exhaust fan, vapor, contaminant occurrence amount of carbon dioxide etc. In kitchen of apartment house. The ventilation rates in the apartment kitchen measured by Tracer Gas Method. And, temperature of when cook by gas table hood lower part 10cm and floor upside 10cm of kitchen central part, 120cm, 210cm heights measure. As ventilation rates measurement result, ventilation number of times was 0.7(number of times/hour) when did not to operate exhaust fan. but we were measured by 2.3(number of times/hour) when drove strongly. As temperature measurement result at cooking by gas table, temperature showed highest in hood lower part 10cm of case that do not operate exhaust fan. Temperature at kitchen central was most low in 10cm height in talc floor, and 210cm were measured highest. Concentration of carbon dioxide is very high by 4,350ppm after measurement time 10 minutes in state who do not operate exhaust fan at cooking by gas table.

• ETRI Journal
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• v.40 no.6
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• pp.813-823
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• 2018

In existing mobile computing environments, users need to choose between their privacy and the services that they can receive from an application. However, existing mobile platforms do not allow users to perform such trade-offs in a fine-grained manner. In this study, we investigate whether users can effectively make utility-privacy trade-offs when they are provided with a multilevel privacy control method that allows them to recognize the different quality of service that they will receive from an application by limiting the disclosure of their private information in multiple levels. We designed a research model to observe users' utility-privacy trade-offs in accordance with the privacy control methods and other factors such as the trustworthiness of an application, quality level of private information, and users' privacy preferences. We conducted a user survey with 516 participants and found that, compared with the existing binary privacy controls, both the service utility and the privacy protection levels were significantly increased when the users used the multilevel privacy control method.

• Journal of Microbiology and Biotechnology
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• v.16 no.11
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• pp.1690-1698
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• 2006

In order to investigate the effect of dissolved oxygen (DO) level on AVM $B_{1a}$ production by a high yielding mutant of Streptomyces avermitilis, five sets of bioreactor cultures were performed under variously controlled DO levels. Using an online computer control system, the agitation speed and aeration rate were automatically controlled in an adaptive manner, responding timely to the oxygen requirement of the producer microorganism. In the two cultures of DO limitation, the onset of AVM $B_{1a}$ biosynthesis was observed to casually coincide with the fermentation time when oxygen-limited conditions were overcome by the producing microorganism. In contrast, this phenomenon did not occur in the parallel fermentations with DO levels controlled at around 30% and 40% throughout the entire fermentation period, showing an almost growth-associated mode of AVM $B_{1a}$ production: AVM $B_{1a}$ biosynthesis under the environments of high DO levels started much earlier than the corresponding oxygen-limited cultures, leading to a significant enhancement of AVM $B_{1a}$ production during the exponential stage. Consequently, approximately 6-fold and 9-fold increases in the final AVM $B_{1a}$ production were obtained in 30% and 40% DO-controlled fermentations, respectively, especially when compared with the culture of severe DO limitation (the culture with 0% DO level during the exponential phase). The production yield ($Y_{p/x}$), volumetric production rate (Qp), and specific production rate (${\bar{q}}_p$) of the 40% DO-controlled culture were observed to be 14%, 15%, and 15% higher, respectively, than those of the parallel cultures that were performed under an excessive agitation speed (350 rpm) and aeration rate (1 vvm) to maintain sufficiently high DO levels throughout the entire fermentation period. These results suggest that high shear damage of the high-yielding strain due to an excessive agitation speed is the primary reason for the reduction of the AVM $B_{1a}$ biosynthetic capability of the producer. As for the cell growth, exponential growth patterns during the initial 3 days were observed in the fermentations of sufficient DO levels, whereas almost linear patterns of cell growth were observed in the other two cultures of DO limitation during the identical period, resulting in apparently lower amounts of DCW. These results led us to conclude that maintenance of optimum DO levels, but not too high to cause potential shear damage on the producer, was crucial not only for the cell growth, but also for the enhanced production of AVM $B_{1a}$ by the filamentous mycelial cells of Streptomyces avermitilis.

• Phonetics and Speech Sciences
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• v.3 no.1
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• pp.3-14
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• 2011

It has been posited that in English, native listeners use the Metrical Segmentation Strategy (MSS) for the segmentation of continuous speech. Strong syllables tend to be perceived as potential word onsets for English native speakers, which is due to the high proportion of strong syllables word-initially in the English vocabulary. This study investigates whether Koreans employ the same strategy when segmenting speech input in English. Word-spotting experiments were conducted using vowel-initial and consonant-initial bisyllabic targets embedded in nonsense trisyllables in Experiment 1 and 2, respectively. The effect of strong syllable was significant in the RT (reaction times) analysis but not in the error analysis. In both experiments, Korean listeners detected words more slowly when the word-initial syllable is strong (stressed) than when it is weak (unstressed). However, the error analysis showed that there was no effect of initial stress in Experiment 1 and in the item (F2) analysis in Experiment 2. Only the subject (F1) analysis in Experiment 2 showed that the participants made more errors when the word starts with a strong syllable. These findings suggest that Koran listeners do not use the Metrical Segmentation Strategy for segmenting English speech. They do not treat strong syllables as word beginnings, but rather have difficulties recognizing words when the word starts with a strong syllable. These results are discussed in terms of intonational properties of Korean prosodic phrases which are found to serve as lexical segmentation cues in the Korean language.